Portsmouth have held further talks with the Premier League aimed at lifting their transfer embargo but the efforts will be in vain unless an agreement over a repayment schedule can be reached with Chelsea over money owed on Glen Johnson.

The club's executive director, Mark Jacob, is understood to have spoken to officials from the Premier League yesterday as part of an ongoing dialogue. Those talks were to update the league on repayment schedules thrashed out with footballing creditors – including Watford and Rennes – and HM Revenue and Customs.

The club still harbour hopes of having the embargo, under which they have been operating since October, lifted for next month's window, with the manager, Avram Grant, in need of revamping his squad. Yet, barring a considerable injection of new investment, the prospects of the Israeli being able to register new players seem slim with no agreement in place with his former club, Chelsea, over the seven-figure fee owed on Johnson's move from Stamford Bridge to Fratton Park in the summer of 2007.

Talks between the clubs are technically "ongoing" though, in reality, they have reached stalemate, with Chelsea understandably seeking their money for a player who has since been sold on to Liverpool at a considerable profit. The Premier League are also very aware that some of Portsmouth's other footballing creditors, most notably the Championship club Watford who are owed money for Tommy Smith and Mike Williamson, are in financial difficulties.

There remains the very real prospect of the league redirecting the next £7m tranche of television revenues, due next month, to Portsmouth's creditors to meet some of the club's liabilities.

The amount owed to other clubs in outstanding transfer fees is higher than the television payment, with the Premier League emerging from talks between Portsmouth's board and its own directors this month far from reassured on the club's future. Its fears were not allayed by Portsmouth's insistence that agreements have been reached over rescheduling payments to a number of clubs, including Udinese over Sulley Muntari, Arsenal over Lassana Diarra and Rennes over John Utaka.

The likelihood remains that, far from strengthening his squad, Grant will have to reduce the club's £1.8m-a-month wage bill next month with high earners such as David James, Utaka and Younes Kaboul potentially made available. The club are due to pay the playing staff's salaries at the end of this month. They have struggled to meet the financial commitments to their squad this season, twice taking out loans to pay the wages, and the new owner, Ali al-Faraj, is seeking to refinance the debt.

The team have struggled on the pitch, perhaps inevitably given the turmoil off it, and, despite securing an unlikely late point at Sunderland on Saturday, they go into Wednesday's meeting at Chelsea bottom of the table and some five points off safety with only three wins from 16 games.